Manually actuated hydraulic jack for compressively applying terminals on electric cables and conductors in general

Abstract

The jack comprises a fixed jaw, rigidly associated with the jack body, and a movable jaw facing said fixed jaw and being connected to a piston sealingly movable inside a cylindrical chamber. In the body, first and second chambers are provided, respectively in communication, through a first delivery conduit and first intake conduit, and through a second delivery conduit and second intake conduit, with the cylindrical chamber and a working fluid reservoir, in the first chamber there being sealingly movable a high pressure piston, whereto is connected a lug passed through the second chamber in sealed relationship therewith, wherein it acts by contact on an elastically biased low pressure piston, the high pressure piston being connected at the free end thereof to an actuating lever handle.

I claim: 
     
       1. A manually actuated hydraulic jack for compressively applying terminals on electric cables and conductors in general, comprising a jack body, a fixed jaw rigidly associated with said jack body, a moving jaw facing said fixed jaw, an actuating lever handle pivoted to said jack body for effecting a forward stroke toward said jack body and a reverse return stroke, a cylindrical chamber in said body, a piston movable within said cylindrical chamber and rigidly connected to said movable jaw, a working fluid reservoir, first and second chambers in said jack body, a first intake conduit and a first delivery conduit for establishing communication between said reservoir and said first chamber and between said first chamber and said cylindrical chamber, second intake conduit and second delivery conduit for establishing communication between said reservoir and said second chamber and between said second chamber and said cylindrical chamber, one-way valving means in said intake and said delivery conduits for controlling said intake and said delivery conduits, a high-pressure piston sealingly movable in said first chamber and pivoted to said actuating handle, a low-pressure piston movable in said second chamber, elastic bias means in said second chamber acting on said low-pressure piston, said high-pressure piston having a lug protruding out of said first chamber toward said second chamber and acting on said low-pressure piston, for urging it, during the forward stroke of the actuating lever handle, to a retracted filling position where said elastic means is compressed wherein said second chamber is filled in use with working fluid through said second intake conduit and said first chamber has discharged working fluid contained therein through said first delivery conduit, said elastic means acting on said low-pressure piston during the reverse stroke of said actuating lever handle for bringing said low-pressure piston in its expanded position to discharge the working fluid filling said second chamber through said second delivery conduit and urge said high-pressure piston in its retracted position where said first chamber is filled with working fluid through said first intake conduit. 
     
     
       2. A manually actuated hydraulic jack according to claim 1, wherein said first and second chambers are positioned in mutual axial alignment relationship. 
     
     
       3. A manually actuated hydraulic jack according to claim 1, wherein said low-pressure piston comprises a cap element of bowl-like shape having a base and defining a seat therein, said base of said bowl-like cap element forming an outer face and an inner face, said lug of said high-pressure piston cooperating with said outer face of said cap element base for urging said low-pressure piston in its retracted position, and said elastic means being at least partially accomodated in said seat defined in said bowl-like cap element and acting on said inner face of said cap element base for urging said low-pressure piston in its expanded position during the reverse stroke of said actuating handle. 
     
     
       4. A manually actuated hydraulic jack for compressively applying terminals on electric cables and conductors in general, comprising a jack body, a fixed jaw rigidly associated with said jack body, a moving jack facing said fixed jack, an actuating lever handle pivoted to said jack body for effecting a forward stroke toward said jack body and a reverse return stroke, a cylindrical chamber in said body, a piston movable in said cylindrical chamber and rigidly connected to said movable jaw, a working fluid reservoir, first and second chambers axially aligned to each other in said jack body, a first intake conduit and a first delivery conduit for establishing communication between said reservoir and said first chamber and between said first chamber and said cylindrical chamber, a second intake conduit and a second delivery conduit for establishing communication between said reservoir and said second chamber and between said second chamber and said cylindrical chamber, one-way valving means in said intake and said delivery conduits for controlling said intake and said delivery conduits, a high-pressure piston sealingly movable in said first chamber and pivoted to said actuating lever handle, a low pressure piston movable in said second chamber, said low pressure piston comprising a cap element of bowl-like shape having a base and defining a seat therein, said cap element base forming an outer face and an inner face, elastic bias means in said second chamber at least partially received in said cap element seat and acting on said inner face of said cap element base, said high-pressure piston having a lug protruding out of said first chamber towards said second chamber and acting on said outer face of said cap-element base for urging said low-pressure piston, during the forward stroke of the actuating lever handle, to a retracted filling position where said elastic means is compressed, said second chamber is filled with working fluid through said second intake conduit and said first chamber has discharged working fluid contained therein through said first delivery conduit, said elastic means acting on said base outer face of the cap element during the reverse stroke of said actuating handle for bringing said low-pressure piston in its expanded position to discharge the working fluid filling said second chamber through said second delivery conduit and urge said high-pressure piston in its retracted position where said first chamber is filled with working fluid through said first intake conduit.